Infrared correlations in the bile acid series

The infrared spectra of a number of esters and free acids in the cholanic acid series have been examined with the aid of a special solvent system which overcomes the problem of solubility. Eleven absorption regions in the 9–12 μ region have been correlated with specific substitution on the steroid nucleus and side chain. In certain cases, perturbations were found when di- or tri-substitution occurred in rings A, B, andJor C.     

Dragons in Pursuit of the EBQ

Some of the objections to the classical model used in the theory of batch quantities are reviewed. They fall broadly into four categories (1) the validity of the model; (2) the determination of cost parameters; (3) criteria; (4) implementation. Some of the objections can be met by minor modifications of the model; others are more fundamental in nature. In multi-product situations the classical model can only provide an initial guidance and must be supplemented be other tools.     

Directing effect of a neighboring hydroxyl substituent on base-catalyzed enolization of a ketone

Evidence is presented that a neighboring hydroxyl substituent may exert a directing effect on the base-catalyzed enolization of a cyclohexanone derivative.     

Acrylnitril-Copolymerisationen. 5. Mitt. Anomale Kinetik und Sekundärreaktionen bei der Copolymerisation mit Vinylchlorid

Ohne Zusammenfassung     

Some aspects of discreteness-of-charge and ion-size effects for ions adsorbed at charged metal/aqueous electrolyte interfaces

It is argued that the self-image potential of an ion adsorbed on a charged metal from an aqueous electrolyte is described in terms of multiple imaging and not single imaging in the metal as proposed by Bockris. The image potential of an isolated ion situated on the i.H.p. in the inner region with a continuously and smoothly varying dielectric profile is calculated. This is compared with the corresponding potential for an inner region model with a discontinuous dielectric profile. It is shown that when the position of the i.H.p. relative to the o.H.p. is changed, the two potentials will in general cross each other such that the discontinuous model has the more negative self-image potential when the i.H.p. approaches the o.H.p. The scaled-particle expression for the entropic contribution due to ion-size effects in the adsorption isotherm of an ion in the inner region is compared with the corresponding Flory-Huggins formula. It is demonstrated that the two theories can give very different results. In particular, when the adsorbed ions are considerably larger than the solvent molecules, it is possible that scaled-particle theory leads to a ‘negative’ ion-size entropy term, which decreases with increase in density of adsorbed ion.